This invention relates generally to stators for use in alternating current motors and more particularly to an improved slot and winding arrangement for such stators.
It is desirable from both cost and weight standpoints to provide stators with cores having yoke sections as small as practicable for the desired electric and magnetic characteristics. The stator coils generally are distributed more or less completely and uniformly around the core and the associated end turns are pressed back and more or less completely cover the adjacent end face of the core.
In most cases this provides .[.a.]. .Iadd.no .Iaddend.problem regarding mounting the motor as the mounting structure may engage the side of the core or the peripheral edge of the core end faces. However, in a number of applications such as, for instance motors to be used in compressor units for refrigeration systems, it can cause substantial problems. Many such units require the use of relatively large mounting pads which engage the end faces of the core and thus the end faces must have appropriate areas free of windings, including end turns to accept these pads.
One method of providing such areas would be to increase the cross-sectional size of the yoke at that position to provide extra end face area. Such an approach is undesirable as it unduly increases the size, weight and cost of the motor.
Prior attempts to solve this problem by distributing the coils in such a manner as to leave suitable areas free of coils have not been completely satisfactory as they generally caused substantial deterioration of the operating characteristics of the motor.